Means for protecting steam boilers against plowing



Oct. 20, 1931. s. HAGA 1,328,138-

MEANS FOR PROTECTING STEAM BOILERS AGAINST FLOWING BACK OF BOILER WATER WHEN FEEDING SYSTEM LEAZIS 7 Filed Aug. 3, 1929 INVENTOR.'

BY @VWM A TTORNEYS UNITED STATES" "PATENT OFFICE SOJ'IRO HAGA,

or1'rokYo-snr, JAPAN MEANS FOR PROTECTING STEAM BOILERS AGAINST FLOWING BACK OF BOILER WATER WHEN FEEDING SYSTEM LEAKS Application filed August The invention relates to means for protecting steam boilers against the low-water or dehciency of boiler water which is caused by the flowing back of water out of the boiler, when defect or leakage occurs in the feedwater system. When the defect or leakage takes place in the feed water system, if the feeding ceases, the boiler water, which is fed till the ordinary working level, is forced back out of the boiler by its own pressure, to cause low water.

it is evident that the low-water is the primary cause of boiler-explosion. The defect or leakage in feeding system takes place mainly in valves, such as check valve, stop valve, without any visible indication, although the boiler is in actual service. Therefore boiler attendants are very often troubled by the low-water which may occur at any time.

The invention is designed for boiler water not to go back from the boiler, although leakage occurs in feeding system, and for alarming the attendant.

An embodiment of the invention is illustrated by way of example in the accompanying single drawing showing a diagrammatical side view partly in section of means applied to a cylindrical boiler.

Referring to the drawing, the boiler 1 is shown by only a fore part of it. The internal feed pipe 2 having a check valve 21 is situated in ordinary position below the working level of boiler water. A part between 3 and l of the internal pipe is projected upwards to the steam space with the two bends 5 and 6. Between these two bends 5 and 6 is provided T-pipe into which the valve casing 8 is secured. The valve casing 8 has a tubular upper end with an open top. In the valve casing 8 there is a valve 9 and the valve spindle 10 which extends between the guide 11 and 1'2 in the said casing. 13 is the seat of the valve 9, and let is a stop secured on the upper end of the valve spindle 10. WVhen the valve 9 drops downwards, it is so adjusted as the stop 1e retains the valve 10 at a short distance above the throat 15 not to close the same. Being disposed within the arm of 3, 1929, Serial No. 383,415, and in. Japan December 18, 1928.

T-pipe '7, a nozzle 16 is made for feed water to assist easy flow.

In actual working of steam boiler, when feed water is pumped into the boiler, we will have the valve 9 pushed upwards and seated on the valve seat 13, closing the passage of feed water, because the feed-water is forced in with excess pressure in the boiler. When the forcing of pump ceases, the said valve 9 will drop down, on account of its own weight, until the stop 1 f engages the upper guide 11, making the entrance of steam to the space in the valve casing 8, T-pipe 7, and the bends 5 and 6 in the internal feed pipe 2, down to the water level in the said internal feed-pipe, that is, the water-level in the boiler.

Thus when feeding ceases, the internal feed ipe is to be interrupted by the steam space in the bends 5 and 6 and T-pipe 7 and &c. which are conducted to the steam space in the boiler. Therefore, if the feeding steam leaks to outside of the boiler, the steam will flow out through the internal pipe 8, by way of bend 5, T-pipe 7, and the valve casing S, alarming the attendant, instead of boiler water flowing through the bend 6 and the pipe Any suitable alarm device may preferably be employed in feed-pipe line through which the steam will flow out. In the drawing, such alarm device is illustrated in an alarm whistle 17 by way of example. As seen from the drawing, when the float chamber is filled with water, the valve 18 will remain in closed state, being raised against its seat by the aid of the float 19 which is well adjusted and is connected to the valve, to prevent the flowing out of the feed water through the float chamber. When leakage occurs in feed line, the water in the float chamber will flow out through the pipe, and then the float 19 which is connected to the valve 18 will come down on the support 20, making the opening of steam, and the whistle 17 will alarm.

Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I claim:

In combination with a steam boiler, a feed water pipe having a check valve therein 'connected to the boiler and having a portion extending Within the same below water level thereof, said portion having parts including an ofiset portion extending above the water level, said offset portion com rising a horizontal portion and a vertica portion opening into the horizontal portion and into the boiler steam space, a check valve for said vertical portion, and a float controlled alarm device connected-to said feed Water pipe on the side of the first mentioned check valve most remote from the boiler.

In testimony whereof I affix my signature.

SOJIRO HAGA. 

